Beezvette

So I took the Vette to the dealer because the battery went dead. This is what happened.

I would doubt it if I had not seen it with my own eyes.

The meter was showing usually between 9 and 15 milliamps draw with frequent spikes to 48. At 48 the spec says the battery will last 16 days. It does that for hours. Tech says he would like to disconnect aftermarket mild to wild, that is the first question GM will ask, so he pulls the fuse and the spike is still there but not so bad, so it seemed. I start the car to verify it is in loud mode; it is. He replaces the fuse and after it settles down with the fuse in, it is pulling 9-10 milliamps never higher than 15. I watch it for a while and it is consistent. He can't explain it; maybe the fuse was not well seated.

Now the battery is on their charger/tester which presumably can accurately tell me if the battery is healthy.

None of this makes sense to me but he can't fix something that is not broken. I'd be interested in comments.

I would like to buy an induction meter to keep an eye on this myself, does anyone know of a reasonably prices unit that can measure milliamps?

C8-Vette

Your initial draw is in the acceptable range. I'm sure you have done this, wait 30 seconds after hooking up the amp meter to the negative terminal. Sometimes the initial reading is high but settles done to 10 to 15 miliamps after 30 seconds or so . I noticed you have an 2010. This problem was common in the 2005's. A TB pointed to a relay in the drivers door. A TECH 2 was able to flash to correct the problem.
I keep a Ctec 3300 hooked up whenever I don't plan on using the car for a few days. You don't want the battery to go dead too often. It will shorten it's life.
Let us know how you make out.
Al

Beezvette

Thanks for the comments. I have a voltmeter that is capable of measuring milli amps, would you be so kind as to tell me what I have to do to use it to measure the draw at home so I can monitor it? Do I need to disconnet the battery?

cclive

Of course the mild to wild needs to be disconnected for an accurate measurement. My car will read a constantly fluctuating reading between 11 and 17ma...so yours is normal when it is in that range. It takes a few minutes for everything to settle down to get down into that range. Mine does not have Onstar, which must draw something in order to keep its' receiver turned on to get door unlocking requests and the like. This may account for the difference. You need to connect the meter and then in a methodical way, start pulling fuses one at a time in order to see which circuit is causing the current jump. 48ma is not a huge amount and if it is only a spike that happens once in a while, it would not bother me. If the 48 is happening alot, then battery life will suffer.
The gold standard in meters is Fluke, but measuring milliamps is not a difficult thing and most less expensive meters will do it. Generally, 'loop type' current meters are not good at measuring small DC currents and are normally used for measuring large AC currents. A meter actually connected in series with the battery is the best way to measure these small DC currents.

brettbolt

You need to disconnect one of the battery cables and put one lead of your meter on the battery terminal and the other on the cable. Then you can measure amps.

C8-Vette

Disconnect the negative terminal. Put the meter on 20 amp setting initially. Connect one terminal of the meter to the negative post the other to the removed negative battery terminal. Reduce the meter settings to the miliamp ranges. Remember to wait at least 30 seconds to get an accurate reading. Acceptable range is less than 20 miliamps.

Beezvette

Thanks I will do that. Does anything need to be reset after disconnecting the battery cable?

Swiftrider08

After disconnecting the battery, the windows will need to be re-indexed (in your owners manual), seat memory will need to be re-set, along with clock and radio.

Do you know if your M2W was installed using the zero drain optional hook-up?

Curious how long your car was sitting before the battery went dead? With a new battery, car sitting in the garage with nothing on and the battery will be dead in about two weeks.

Keep a battery tender attached when not driving on a consistent basis.

Beezvette

Oddly, after reseating the m2w fuse, the spikes to 48 went away and it was staying consistently in a normal range. That is why I want to monitor it.

Beezvette

I do not think I used the zero drain option but as I recall, keeping it in loud mode has the same affect, am I incorrect?

Car sat for 2 weeks with the m2w in quiet mode which is a drain and documented as such by the manufacturer. According to the specs the tech showed me today, a 50 m-amp draw will kill the battery in about 2 weeks, so if it only lasts that long there is a substantial drain somewhere beyond the normal 10-20 m amps.

I think I will go re read the m2w documentation, although after he reseated the fuse the drain was 15 or lower, no spikes and I watched it for about 15 minutes. Odd.

Gearhead Jim

As mentioned, you need to re-index the windows. Be sure to leave your window or door open, or partly open, so you don't need to force the glass past the weatherstrip when you re-enter the car.

1Corvette

Here is the best way to do a parasitic drain test. Use the tool at this link: http://www.amazon.com/Side-Battery-M...=pd_sim_auto_1 or something similar. Hook it to your negative battery terminal on one end and the negative battery cable on the other end. Snug down the **** and start the engine. Let it run a couple of minutes or better yet drive it a few miles. Shut it down normally and open the hood and close the door. The car will start to "go to sleep" now over the next several minutes. Take your DVOM set to "amps" preferably a 5-10 amp setting so you don't blow the fuse. Connect it on both sides of the tool. It should read near "0". Now twist the **** to open the tool forcing any amperage drain to go through the meter and read the results. It may take 20 - 30 minutes for it to completely go to sleep. Sorry, I don't have a service manual on this car so don't know the specs or total time to reach minimum draw. Lastly, don't forget to tighten the **** when you are done and remove your meter. If you don't, it will blow the fuse in your meter as soon as you open the door. Good luck!

Beezvette

Thanks!!! So am I correct - this device eliminates the need to remove the cable but will redirect power through the meter. Does it kill the power temporarily when it makes the switch so the windows still have to be reindexed etc?

C8-Vette

Before you kill the battery leave the windows down about 2 inches. If you don't , you may catch the window on the molding when opening the door. Re-indexing the windows take about 10 seconds. The only thing tou will lose is the window indexing. Seats, radio settings etc. remain unchanged due to flash memory.

Surviving 67

I've read a lot of threads about the "dead battery syndrome" so I thought I would share my experience. I've only driven my 2010 GS since September one time and that was on a 20 mile round trip to work. When I got in it to drive I was suprised that the battery wasn't dead because it had been sitting for close to a month without the charger on it.

Last week I decided I was going to drive it on the weekend so in the middle of the week I thought I should hook up the charger to it. I was pleasantly suprised to see that the battery wasn't dead. For grins I got out the meter and checked the voltage and it was @ 11.5 volts. I put the charger on it anyway but it had been sitting for at least 6 weeks. The car is totally stock with zero changes to anything.

Bill

Nice Ride

I am not a mechanic and based on the reports from some about nice to have modes like wild to mild I guess it is fine to pull fuses etc. to get the best from NPP. That said I don't like doing that. These cars are designed to work best as built and altering the electrical system is just asking for problems. I have NPP on my 2011 and am content to listen to it when I kick up the RPM. Wouldn't it be nice to see Chevy add a simple on/off switch to get the best from NPP. Much better than having most people play around with electrical systems.

cclive

I'll bet that Chevy cannot put an on/off switch on the NPP because of sound regulations. The way it is set up, it passes when driven on the loop set up by the government for testing. Giving the driver the option would mess that up....similar to the skip-shift system.

LeoDelC

None of the posts say anything about where the fob is when making the current measurement. If the fob is in a position where it is being picked up by the reciever, I would expect there might be a different level of activity in the computer and hence a different current draw than if the fob is out of range.

I have not tried this myself, but has anyone tried measuring the current draw with and without a fob in range?

cclive

Fob will not have any effect unless one of its' buttons is being pushed.

C8-Vette